This is an excellent article by Anthony Ha on the 23rd March over at Mobilebeat.

iPad textbook startup Inkling just announced that it has won financial backing from the two biggest names in the textbook business — McGraw-Hill and Pearson.

Founder and chief executive Matt MacInnis said Inkling’s goal involves using the content of an existing textbook as a skeleton, then “casting off the shackles of the book” and adding interactive and multimedia content that could only work on the iPad. We first covered Inkling right after the announcement of the iPad in January of last year. The San Francisco startup has now released 14 textbooks, MacInnis said, and it should be up to more than 100 titles by this fall.

There are other companies building iPad textbooks, MacInnis acknowledged. Competitors include ScrollMotion, and educational tablet-maker Kno is reportedly shifting its efforts from hardware to software. But he argued that everyone else is basically adding limited features to a PDF of the textbook and that these e-books are basically developed by the publishers’ business divisions without much input from the original textbook creators. Inkling, on the other hand, wants to publish apps that feel like they were truly built for the iPad, which usually means working with the books’ authors to create new content.

“It only gets interesting when the content itself changes and begins to respond to your fingertips,” MacInnis said.

You can see an example of an Inkling app in-action in the video below. Thanks to the backing of McGraw-Hill and Pearson, as well as partnerships with John Wiley & Sons, W.W. Norton, and Wolters Kluwer, Inkling now has access to “95 percent of the content universe,” MacInnis said — though the company’s actual production is far behind that amount, since it doesn’t have the resources to convert every title from every publisher. For now, he said, Inkling remains very involved in the digital textbook-creation process, because it wants to ensure that the early apps are high quality. But as time goes on it will move to a more self-service model.

The size of the round was not disclosed, except that it was a “multimillion dollar” financing. Previous investors Sequoia Capital, Felicis Ventures (which also invested in VentureBeat), Kapor Capital, and Sherpalo Ventures also participated in the new funding.